AI 中文总结
研究高空平台站辅助太赫兹卫星通信系统在多种不利条件下的性能，采用可变增益放大转发协议，通过获取相关函数评估系统界限，研究硬件损伤等因素对性能的影响，揭示了硬件损伤致性能下降及不同条件下系统性能特点。
AI 中文摘要
在卫星-空中-地面通信系统中利用太赫兹（THz）频段是实现全球连接和满足第六代网络极高数据速率要求的一个有前景的解决方案。当前文献中，非理想设备对太赫兹卫星-空中-地面通信系统性能的影响尚未被探索，而这对实际应用至关重要。本文分析了在不同大气条件下，存在α-μ衰落、指向误差、吸收损耗和硬件损伤时，高空平台站（HAPS）辅助的太赫兹卫星通信系统的性能。假设在HAPS节点（系统）采用可变增益放大转发协议，并选择能提供最大端到端信噪比（SNR）的HAPS系统进行传输。为评估系统的中断、渐近中断和遍历容量界限，获得了与端到端SNR上限相关的概率密度函数、累积分布函数（CDF）和渐近CDF。通过这些统计数据，研究了硬件损伤水平、天顶角和大气条件对系统性能的影响。结果表明，硬件损伤会导致中断性能的功率损失并降低系统容量。此外，还表明在高SNR区域，中断概率取决于衰落或指向误差特性，并且在HAPS到地面链路中，无论大气条件如何，较低天顶角时系统性能几乎保持不变。
英文摘要
The utilization of terahertz (THz) frequencies in satellite-aerial-ground communication systems stands out as a promising solution to accomplish both global connectivity and extreme data rates requirements of the sixth-generation networks. In the current literature, the impact of non-ideal equipment on the performance of THz satellite-aerial-ground communication systems remains unexplored, which is critical for practical implementations. Hence, this paper analyzes the performance of high-altitude platform station (HAPS)-aided THz satellite communication system in the presence of $α$-$μ$ fading, pointing errors, absorption loss, and hardware impairments for different atmospheric conditions. In the system of interest, it is assumed that variable-gain amplify-and-forward protocol is utilized at HAPS nodes (systems), and the HAPS system, which provides the maximum end-to-end signal-to-noise ratio (SNR), is selected for transmission. To evaluate the outage, asymptotic outage, and ergodic capacity bounds for the system, the probability density function, cumulative distribution function (CDF), and asymptotic CDF related to the upper bound of the end-to-end SNR are obtained. By using these statistics, the effects of hardware impairment levels, zenith angles, and atmospheric conditions on the system performance are examined. The results have shown that hardware impairments cause power loss in outage performance and reduce the system capacity. Moreover, it is demonstrated that the outage probability depends on either fading or pointing error characteristics in high SNR region and also that the system performance almost remains the same for lower zenith angles in HAPS-to-ground link regardless of the atmospheric conditions.
